Shape controllable MoS2 nanocrystals prepared by the single precursor route for electrocatalytic hydrogen evolution

MoS2 has attracted great attention as a prospective electrocatalyst for generating hydrogen via water electrolysis due to its abundant and inexpensive sources. However, bulk MoS2 has weak electrocatalytic activity because of its low electrical conductivity and few edge-active sites. Controllable synthesis of MoS2 with ultrasmall size or complex morphology may be an available strategy to boost its conductivity and edge-active sites. Herein, a facile single-precursor strategy was developed to prepare nanoscale MoS2 with various morphologies, including quantum dots, nanorods, nanoribbons, and nanosheets. In-depth studies show that the formation of MoS2 with various shapes is determined by both kinetic and thermodynamic factors such as reaction time and temperature. Electrocatalytic tests reveal that MoS2 quantum dots have high electrocatalytic performance with a low overpotential of 255 mV and a small Tafel slope of 66 mV dec(-1) due to the abundant exposed active edges and excellent intrinsic conductivity.

Automated summary

MoS2 has attracted attention as an electrocatalyst for hydrogen generation. However, bulk MoS2 has weak electrocatalytic activity due to its low electrical conductivity and few active sites. This study develops a method to synthesize nanoscale MoS2 with various morphologies to enhance its conductivity and active sites. Electrochemical tests reveal that MoS2 quantum dots exhibit high electrocatalytic performance due to their abundant active edges and excellent conductivity.